Closure assemblies employing a tear off band with a pull tab have been provided for use with containers generally. These devices have found particular use in the pharmaceutical industry.
Pharmaceutical containers for liquids or for solids which are reconstituted by the addition of liquids have a pierceable closure member such as a disc or stopper formed of rubber or other elastomers. They are also provided with a metallic cap, preferably aluminum, to hold the stopper in place.
In some designs, an inner central removable disc is detachably secured to the outer annular top portion of a cap through the use of fracturable bridges. Thus, by lifting off this center disc portion, the stopper area is exposed and access to the contents is provided.
Among these designs are those shown in U.S. Pat. No. 4,071,274, in which the cover is removed by pushing with the thumb. U.S. Pat. No. 3,547,297 discloses a cap with a lift off top and U.S. Pat. No. 3,587,897 discloses a similar cap, including a depending skirt which is adapted to be crimped inwardly at its lower edge around or over the outer bead finish on the container to further secure the stopper or disc in place.
Still another alternative technique is the use of a tear off cap which provides a hinged central portion at the top of the cap to provide a grip for tearing off the cover over the stopper and around the top of the container. These systems include a cap portion and a pull tab section with lines or scores for guiding the direction or the tear. These tear off closure designs have not been found to be universally acceptable, particularly in high speed assembly systems because of possible breakage during manufacture. The junction between the pull tab and the cap is often destroyed or damaged during high speed assembly. The disc or pull tab also has a tendency to become damaged when the stopper itself is inserted into the closure. In addition, pull tabs and discs fall out and lines or scores open or bend during hoppering and sealing procedures.
U.S. Pat. No. 4,471,879 describes a combination of the over cap which can be removed by the thumb and includes a conventional tear off cover having a hinged central portion and a pull tab for removing the cover. That patent provides an additional advantage of color coding various portions of the apparatus to convey information to the pharmacist or other hospital personnel using the container.
It has become clear that the assembly of pharmaceutical products in containers as described above in the most economical manner possible allows the supplier to pass on economies and efficiencies to the ultimate user of the product. More importantly, when a design is provided which is free from problems during hoppering, sealing, and other assembly steps, manufacturing efficiencies allow the manufacturer to be much more competitive and supplying what is now becoming a major article of commerce.
Even though the pharmaceutical industry in intensely concerned about the integrity of the product produced, including the closure components, it is also driven by the need for greater efficiency and speed. For example, if a process which is otherwise quite reliable can be operated at a significantly faster average operating speed, the unit cost is reduced without any adverse effect on product quality and integrity.
Accordingly, there appear to be two conflicting goals in efforts made to improve the application of closures to containers, particularly those for high speed assembly in the pharmaceutical industry. On the one hand, it is desirable to increase the strength and durability of the closures prior to assembly, to avoid downtime and a significant quantity of rejected products. On the other hand, the need for easy, quick and convenient opening of the container requires easily broken scoring. This is particularly true because the user of the product has become dependant upon a certain degree of ease, convenience and efficiency in opening containers.
One problem with some prior art closures is that scoring is provided which requires that the ring be turned in a specified direction, such as, for example, to the right. If the ring is pulled to the left, the ring will come off, leaving the band still attached to the container.
Thus, it would be a great advance in the art if a new and improved design could be provided which would allow for effective and rapid sealing with minimum damage to the closure while at the same time maintain or even improve the ease of use of the container by the final user.
These objects will become more apparent upon a reading of the description which follows.